Thrust reverser with blocker door folding linkage

ABSTRACT

An assembly is provided for an aircraft propulsion system. This assembly includes a fixed structure, a translating structure, a blocker door and a folding linkage. The translating structure is configured to move between a stowed position and a deployed position. The blocker door is pivotally attached to the translating structure at a first pivot joint. The folding linkage links the blocker door to the fixed structure. The folding linkage includes a member pivotally attached to the blocker door at a second pivot joint that is radially outboard of a skin of the blocker door when the translating structure is in the stowed position. The second pivot joint is radially outboard of the first pivot joint when the translating structure is in the stowed position.

BACKGROUND 1. Technical Field

This disclosure relates generally to an aircraft propulsion system and,more particularly, to a thrust reverser for an aircraft propulsionsystem.

2. Background Information

An aircraft propulsion system such as a turbofan gas turbine engine mayinclude a thrust reverser to aid in aircraft landing. A typical thrustreverser includes a plurality of blocker doors, which pivot inward intoa bypass duct from stowed positions to deployed positions. The pivotingof the blocker doors may be facilitated with use of drag links. Atypical drag link is connected to an inner fixed structure at one end,and connected to a respective blocker door at the other end. As aresult, even when the thrust reverser is not being used, the drag linksextend across the bypass duct and thereby increase bypass duct drag andreduce engine efficiency during typical engine operation; e.g., duringcruise. There is a need in the art therefore for an improved thrustreverser with reduced drag.

SUMMARY OF THE DISCLOSURE

According to an aspect of the present disclosure, an assembly isprovided for an aircraft propulsion system. This assembly includes afixed structure, a translating structure, a blocker door and a foldinglinkage. The translating structure is configured to move between astowed position and a deployed position. The blocker door is pivotallyattached to the translating structure at a first pivot joint. Thefolding linkage links the blocker door to the fixed structure. Thefolding linkage includes a member pivotally attached to the blocker doorat a second pivot joint that is radially outboard of a skin of theblocker door when the translating structure is in the stowed position.The second pivot joint is radially outboard of the first pivot jointwhen the translating structure is in the stowed position.

According to another aspect of the present disclosure, another assemblyis provided for an aircraft propulsion system. This assembly includes afixed structure, a translating structure, a blocker door and a foldinglinkage. The translating structure is configured to translate between astowed position and a deployed position. The blocker door is pivotallyattached to the translating structure. The folding linkage links theblocker door and the fixed structure. The folding linkage includes aroller that engages the translating structure when the translatingstructure moves from the stowed position to an intermediate positionbetween the stowed position and the deployed position.

According to still another aspect of the present disclosure, a method isprovided during which method an aircraft propulsion system is providedthat includes a fixed structure, a translating structure, a blocker doorand a folding linkage. The blocker door is pivotally attached to thetranslating structure. The folding linkage connects the blocker door tothe fixed structure. The translating structure moves from a stowedposition towards a deployed position. The blocker door moves relative tothe translating structure. The folding linkage is configured to initiatethe moving of the blocker door substantially simultaneously withinitiation of the moving of the translating structure.

The roller may be configured to facilitate pivoting of the blocker dooras the translating structure translates from the stowed position to theintermediate position.

The folding linkage may include a link arm and a crank arm. The link armmay link and be pivotally attached to the fixed structure and the crankarm. The crank arm may link the link arm and the blocker door. The crankarm may be pivotally attached to the blocker door at the second pivotjoint.

The crank arm may be configured with a roller that engages thetranslating structure during movement of the translating structure fromthe stowed position to a partially deployed position that is between thestowed position and the deployed position.

The roller may disengage the translating structure when the crank armengages a stop on the blocker door.

The folding linkage may be configured to initiate movement of theblocker door relative to the translating structure substantiallysimultaneously with initiation of movement of the translating structurefrom the stowed position towards the deployed position.

The folding linkage may be configured to pivot the blocker door radiallyinwards as soon as the translating structure begins to translate axiallyfrom the stowed position towards the deployed position.

The folding linkage may be configured as or otherwise include abi-folding linkage.

The assembly may further include a fixed cascade structure.

The blocker door may be one of a plurality of blocker doors. The foldinglinkage may be one of a plurality of folding linkages. Each of theblocker doors may be associated with a single one of the foldinglinkages.

The blocker door may extend laterally between opposing blocker doorsides. The folding linkage may be aligned laterally midway between theopposing blocker door sides.

The folding linkage may be nested within a channel in the blocker doorand within a channel in the translating structure when the translatingstructure is in the stowed position.

The moving of the blocker door relative to the translating structure mayinclude pivoting the blocker door radially inwards into a bypassflowpath of the aircraft propulsion system.

The blocker door may pivot radially inwards as soon as the translatingstructure begins to translate axially from the stowed position towardsthe deployed position.

The blocker door may be pivotally attached to the translating structureat a first pivot joint. The folding linkage may be pivotally attached tothe blocker door at a second pivot joint. The second pivot joint may belocated radially outboard of the first pivot joint when the translatingstructure is in a stowed position.

The engagement between the roller and the translating structure mayinitiate the movement of the blocker door substantially simultaneouslywith the initiation of the movement of the translating structure.

The foregoing features and the operation of the invention will becomemore apparent in light of the following description and the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an aircraft propulsion system witha thrust reverser in a stowed position, in accordance with variousembodiments;

FIG. 2 is a schematic illustration of the aircraft propulsion systemwith the thrust reverser in a deployed position, in accordance withvarious embodiments;

FIG. 3 is a side-sectional illustration of an aft portion of theaircraft propulsion system in FIG. 1, in accordance with variousembodiments;

FIG. 4 is a side-sectional illustration of an aft portion of theaircraft propulsion system in FIG. 2, in accordance with variousembodiments;

FIGS. 5A-5H illustrate a sequence of the thrust reverser moving from astowed position to a deployed position, in accordance with variousembodiments; and

FIG. 6 is a flow diagram of a method for operating the assembly of FIG.3, in accordance with various embodiments.

DETAILED DESCRIPTION

FIG. 1 illustrates an aircraft propulsion system 10 for an aircraft suchas, but not limited to, a commercial airliner or cargo plane. Thepropulsion system 10 includes a nacelle 12 and a gas turbine engine.This gas turbine engine may be configured as a high-bypass turbofanengine. Alternatively, the gas turbine engine may be configured as anyother type of gas turbine engine capable of propelling the aircraftduring flight.

The nacelle 12 is configured to house and provide an aerodynamic coverfor the gas turbine engine. An outer structure of the nacelle 12 extendsalong an axial centerline 14 between a nacelle forward end 16 and anacelle aft end 18. The nacelle 12 of FIG. 1 includes a nacelle inletstructure 20, one or more fan cowls 22 (one such cowl visible in FIG. 1)and a nacelle aft structure 24, which is configured as part of orincludes a thrust reverser 26.

The inlet structure 20 is disposed at the nacelle forward end 16. Theinlet structure 20 is configured to direct a stream of air through aninlet opening 28 at the nacelle forward end 16 and into a fan section ofthe gas turbine engine.

The fan cowls 22 are disposed axially between the inlet structure 20 andthe aft structure 24. Each fan cowl 22 of FIG. 1, in particular, isdisposed at (e.g., on, adjacent or proximate) an aft end 30 of astationary portion of the nacelle 12, and extends forward to the inletstructure 20. Each fan cowl 22 is generally axially aligned with a fansection of the gas turbine engine. The fan cowls 22 are configured toprovide an aerodynamic covering for a fan case 32. Briefly, this fancase 32 circumscribes the fan section and partially forms a forwardouter peripheral boundary of a bypass flowpath 34 (see FIGS. 3 and 4) ofthe propulsion system 10.

The term “stationary portion” is used above to describe a portion of thenacelle 12 that is stationary during propulsion system 10 operation(e.g., during takeoff, aircraft flight and landing). However, thestationary portion may be otherwise movable for propulsion system 10inspection/maintenance; e.g., when the propulsion system isnon-operational. Each of the fan cowls 22, for example, may beconfigured to provide access to components of the gas turbine enginesuch as the fan case 32 and/or peripheral equipment configured therewithfor inspection, maintenance and/or otherwise. In particular, each of fancowls 22 may be pivotally mounted with the aircraft propulsion system 10by, for example, a pivoting hinge system. Alternatively, the fan cowls22 and the inlet structure 20 may be configured into a single axiallytranslatable body for example. The present disclosure, of course, is notlimited to the foregoing fan cowl configurations and/or access schemes.

The aft structure 24 includes a translating sleeve 36 for the thrustreverser 26. The translating sleeve 36 of FIG. 1 is disposed at thenacelle aft end 18. This translating sleeve 36 extends axially along theaxial centerline 14 between a forward end 38 thereof and the nacelle aftend 18. The translating sleeve 36 is configured to partially form an aftouter peripheral boundary of the bypass flowpath 34. The translatingsleeve 36 may also be configured to form a bypass nozzle 40 for thebypass flowpath 34 with an inner structure 42 of the nacelle 12 (e.g.,an inner fixed structure (IFS)), which nacelle inner structure 42 housesa core of the gas turbine engine.

The translating sleeve 36 of FIG. 1 includes a pair of sleeve segments(e.g., halves) arranged on opposing sides of the propulsion system 10(one such sleeve segment visible in FIG. 1). The present disclosure,however, is not limited to such an exemplary translating sleeveconfiguration. For example, the translating sleeve 36 may alternativelyhave a substantially tubular body. For example, the translating sleeve36 may extend more than three-hundred and thirty degrees (330°) aroundthe centerline 14.

Referring to FIGS. 1 and 2, the translating sleeve 36 is an axiallytranslatable structure. Each translating sleeve segment, for example,may be slidably connected to one or more stationary structures (e.g., apylon and a lower bifurcation) through one or more respective trackassemblies. Each track assembly may include a rail mated with a trackbeam; however, the present disclosure is not limited to the foregoingexemplary sliding connection configuration.

With the foregoing configuration, the translating sleeve 36 maytranslate axially along the axial centerline 14 and relative to thestationary portion. The translating sleeve 36 may thereby move axiallybetween a forward stowed position (see FIG. 1) and an aft deployedposition (see FIG. 2). In the forward stowed position, the translatingsleeve 36 provides the functionality described above. In the aftdeployed position, the translating sleeve 36 at least partially (orsubstantially completely) uncovers at least one or more other componentsof the thrust reverser 26 such as, but not limited to, a fixed cascadestructure 44. In addition, as the translating sleeve 36 moves from thestowed position to the deployed position, one or more blocker doors 46(one visible in FIGS. 3 and 4) arranged with the translating sleeve 36may be deployed to divert bypass air from the bypass flowpath 34 andthrough the cascade structure 44 to provide reverse thrust.

FIG. 3 is a partial side sectional illustration of an assembly 48 forthe propulsion system 10 with the thrust reverser 26 in a stowedposition. FIG. 4 is a partial side sectional illustration of theassembly 48 with the thrust reverser 26 in a deployed position. Thisassembly 48 of FIGS. 3 and 4 includes a nacelle fixed structure 50, anacelle translating structure 52 and a thrust reverser blocker doorassembly 54.

The fixed structure 50 is located at the aft end 30 of the stationaryportion of the nacelle 12. The fixed structure 50 of FIGS. 3 and 4includes a bullnose 56 and an internal nacelle support structure 58. Thebullnose 56 is configured to provide a smooth aerodynamic transitionfrom a bypass flowpath 34 of the aircraft propulsion system 10 to athrust reverser duct, which extends axially between the supportstructure 58 and the translating structure 52 (see FIG. 4). The supportstructure 58 circumscribes and supports the bullnose 56. The supportstructure 58 also provides a base to which the cascade structure 44 maybe mounted. The cascade structure 44 may thereby project axially aftfrom the support structure 58. With such a configuration, when thetranslating structure 52 is in the stowed position of FIG. 3, thecascade structure 44 is located within an internal cavity 60 of thetranslating structure 52. When the translating structure 52 is in thedeployed position of FIG. 4, the cascade structure 44 is uncovered andlocated within the thrust reverser duct.

The translating structure 52 is configured as or otherwise includes thetranslating sleeve 36. The translating sleeve 36 of FIGS. 3 and 4includes an outer panel 62, and inner panel 64 and an internal supportstructure 66. The outer panel 62 is configured to form a portion of anouter aerodynamic surface 68 of the nacelle 12 adjacent the bypassnozzle 40 (see FIG. 1). The inner panel 64 is configured to form aportion of an outer peripheral boundary of the bypass flowpath 34adjacent the bypass nozzle 40. The internal support structure 66 ispositioned radially between the outer panel 62 and the inner panel 64.The internal support structure 66 is disposed with the internal cavity60, which is radially between the outer panel 62 and the inner panel 64.The internal cavity 60 extends axially aft into the translating sleeve36 from its forward end 38.

The door assembly 54 of FIG. 4 includes the one or more blocker doors 46(one visible in FIG. 4), which are arranged circumferentially about thecenterline 14. The door assembly 54 also includes at least one foldinglinkage 70 associated with each blocker door 46.

Each blocker door 46 extends laterally (e.g., circumferentially and/ortangentially) between opposing blocker door sides 72. Each blocker door46 extends longitudinally between a first blocker door end 74 and asecond blocker door end 76. The blocker door 46 is pivotally attached tothe translating structure 52 and, more particularly, the internalsupport structure 66 of the translating sleeve 36 at one or more pivotjoints 78; e.g., via hinges. These pivot joints 78 are respectivelylocated at the opposing blocker door sides 72. The pivot joints 78 arealso located generally at the first blocker door end 74. With thisconfiguration, each blocker door 46 is configured to move (e.g., pivot)radially inwards from the stowed position of FIG. 3 to the deployedposition of FIG. 4. In the stowed position of FIG. 3, the blocker door46 may be mated with, nested in a respective pocket in the translatingstructure 52. A surface 80 of the blocker door 46 may thereby bepositioned approximately flush with an inner surface 82 of the innerpanel 64. In the deployed position of FIG. 4, the blocker door 46projects radially downward from the translating structure 52 into thebypass flowpath 34.

The folding linkage 70 may be configured as a bi-folding linkage. Thefolding linkage 70 of FIG. 4, for example, includes a rigid, unitarylink arm 84 and a rigid, unitary crank arm 86. The folding linkage 70also includes a roller 88, or other carriage device, configured with thecrank arm 86. Alternatively, the roller 88 may be replaced with a fixedblunt edge end. For example, the crank arm 86 may terminate with theblunt edge end, where a curved surface of this end essentially mimics acurved surface of the roller 88. In such embodiments, a wear surface maybe added to a portion of the sleeve 36 that engages the blunt edge end.Still alternatively, the roller 88 may be replaced with a track andguide assembly, or any other suitable assembly.

Referring still to FIG. 4, the link arm 84 extends between a first(e.g., forward) link arm end 90 and a second (e.g., aft) link arm end92. The link arm 84 is pivotally attached to the fixed structure 50 viaa first pivot joint 94 (e.g., a hinged, clevis connection), which joint94 is located at the first link arm end 90 and on, for example, thebullnose 56. The link arm 84 is pivotally attached to the crank arm 86via a second pivot joint 96 (e.g., a hinged, clevis connection), whichjoint 96 is located at the second link arm end 92 and a first crank armend 98 of the crank arm 86. The link arm 84 thereby mechanicallyconnects (e.g., links) the fixed structure 50 with the crank arm 86.

The crank arm 86 extends along a first trajectory from its first crankarm end 98 to a first elbow 100. The crank arm 86 then extends along asecond trajectory from the first elbow 100 to a second elbow 102, whichsecond trajectory may be approximately (e.g., +/−5-10 degrees)perpendicular to the first trajectory. The crank arm 86 then extendsalong a third trajectory from the second elbow 102 to a second crank armend 104, which third trajectory may be approximately (e.g., +/−5-10degrees) perpendicular to the second trajectory and approximately (e.g.,+/−5-10 degrees) parallel, but not coaxial, with the first trajectory.The crank arm 86 is pivotally attached to a respective blocker door 46via a third pivot joint 106 (e.g., a hinged, clevis connection), whichjoint 106 is located at the second elbow 102 and radially outboard(e.g., radially outside) of a skin 107 of the blocker door 46 when thetranslating structure 52 is stowed as shown, for example, in FIG. 3. Theroller 88 is rotatably connected to the crank arm 86 via a roller joint108, which joint is located at the second crank arm end 104. The rollerjoint 108 is located (e.g., approximately midway) between the firstblocker door end 74 and the second blocker door end 76 and forward ofthe pivot joints 96 and 106 when the thrust reverser is in the stowedposition. The roller joint 108 and, thus, the folding linkage 70 may bealigned laterally (e.g., midway) between the opposing blocker door sides72.

FIGS. 5A-5H illustrate a sequence of the thrust reverser 26 deploying,where the translating structure 52 is in the stowed position in FIG. 5Aand the translating structure 52 is in the deployed position in FIG. 5H.In the stowed position of FIG. 5A, each blocker door 46 is nested withina respective pocket in the translating structure 52. In addition, eachfolding linkage 70 is folded and nested in a channel in the respectiveblocker door 46 and a respective channel in the translating structure52. With this configuration, the folding linkage 70 is tucked away andout of the bypass flowpath 34 then the thrust reverser 26 is not beingused. By contrast, a drag link of a typical prior art thrust reverserextends across a bypass duct even when the thrust reverser is not beingused, which increases drag and, thus, reduces engine efficiency duringnominal operation.

During deployment, movement of each blocker door 46 is actuated by axialmovement of the translating structure 52. In particular, as thetranslating structure 52 moves axially aft from its stowed positiontowards the deployed position, the translating structure 52 pulls theblocker doors 46 aft. To compensate for the increased axial distancebetween the blocker doors 46 and the fixed structure 50, each foldinglinkage 70 begins to unfold. More particularly, the second link arm end92 pivots about the first pivot joint 94 and moves radially inward. Thefirst crank arm end 98 correspondingly pivots about the third pivotjoint 106 and moves radially inward. This pivoting of the crank arm 86,in turn, causes the second crank arm end 104 to also pivot about thethird pivot joint 106. As a result, the roller 88 is pushes radiallyagainst the internal support structure 66 of the translating structure52, which causes the third pivot joint 106 and, thus, the blocker door46 to move radially inward and away from the internal support structure66. More particularly, the engagement of the roller 88 against theinternal support structure 66 causes the second blocker door end 76 topivot about the pivot joints 78 and move radially inward. With thisconfiguration, the folding linkage 70 is configured to initiate movement(e.g., pivoting) of the respective blocker door 46 substantiallysimultaneously (e.g., +/−time associated with standard industryengineering tolerances) with the initiation of the aft translation ofthe translating structure 52 from the stowed position towards thedeployed position. In other words, the elements 46 and 52 are configuredto begin moving at the same time.

The roller 88 continues to cause the respective blocker door 46 to pivotinward until the crank arm 86 reaches and engages a stop 110 configuredinto the blocker door 46 associated with an intermediate translatingstructure 52 position; e.g., see FIG. 5D. Once the crank arm 86 reachesand engages this stop 110, the crank arm 86 no longer moves relative tothe blocker door 46 as shown in FIGS. 5E-H. Rather, the crank arm 86functions as a fixed member of the blocker door 46. The crank arm 86thereby pivots the blocker door 46 radially inwards into the bypassflowpath 34 without moving relative to the blocker door 46.

It is worth noting, referring to FIG. 3, the pivot joints 78 may belocated radially inward of the pivot joint 106 when the thrust reverser26 and its elements are stowed. This configuration can be implementedbecause the crank arm 86 and the associated roller 88 push the foldinglinkage 70 radially inward as described above and, thereby, prevent thefolding linkage 70 from binding.

In some embodiments, the internal support structure 66 may be configuredwith a wear plate to engage with the roller 88.

FIG. 6 is a flow diagram of a method 600 for operating the assembly 48of FIG. 3. In step 602, the aircraft propulsion system 10 and itsassembly 48 are provided. In step 604, the translating structure 52 ismoved (e.g., translated axially) from its stowed position of FIG. 5Atowards (or to) its deployed position of FIG. 5H using one or moreactuators; e.g., linear actuators. In step 606, each blocker door 46 ismoved relative to the translating structure 52. Herein, the term“relative” describes movement between the blocker door 46 and thetranslating structure 52. For example, while both the blocker door 46and the translating structure move with each other axially in thesequence of FIGS. 5A-5H, the blocker door also pivots radially inwardsaway from the translating structure 52 and into the bypass flowpath 34.Of course, in other embodiments, the elements 46 and 52 may also oralternatively travel at different axial speeds and, thus, move axiallyrelative to one another. As illustrated by the sequence of FIGS. 5A-5H,the movement (e.g., pivoting) of the blocker doors 46 is initiatedsubstantially simultaneously (e.g., instantaneously) with initiation ofthe movement of the step 604. Thus, as soon as the translating structure52 begins to move axially from the stowed position to the deployedposition, each blocker door 46 begins to pivot radially inward anddeploy.

The terms “radially”, “axially”, “upstream”, “downstream”, “inner” and“outer” and variants thereof are used herein to orientate the componentsof the aircraft propulsion system 10 described above relative to theturbine engine, the nacelle 12 and/or its axial centerline 14. Forexample, the term “radially inward” and variants thereof may describemovement of a component in a radial direction towards the centerline 14,or a position radially towards the centerline 14. By contrast, the term“radially outward” and variants thereof may describe movement of acomponent in a radial direction away the centerline 14, or a positionradially away the centerline 14.

While various embodiments of the present invention have been disclosed,it will be apparent to those of ordinary skill in the art that many moreembodiments and implementations are possible within the scope of theinvention. For example, the present invention as described hereinincludes several aspects and embodiments that include particularfeatures. Although these features may be described individually, it iswithin the scope of the present invention that some or all of thesefeatures may be combined with any one of the aspects and remain withinthe scope of the invention. Accordingly, the present invention is not tobe restricted except in light of the attached claims and theirequivalents.

What is claimed is:
 1. An assembly for an aircraft propulsion system,comprising: a fixed structure; a translating structure configured tomove between a stowed position and a deployed position; a blocker doorpivotally attached to the translating structure at a first pivot joint;and a folding linkage linking the blocker door to the fixed structure,the folding linkage comprising a member pivotally attached to theblocker door at a second pivot joint that is radially outboard of a skinof the blocker door when the translating structure is in the stowedposition; wherein the second pivot joint is radially outboard of thefirst pivot joint when the translating structure is in the stowedposition.
 2. The assembly of claim 1, wherein the folding linkagecomprises a link arm and a crank arm; the link arm links and ispivotally attached to the fixed structure and the crank arm; and thecrank arm links the link arm and the blocker door, and is pivotallyattached to the blocker door at the second pivot joint.
 3. The assemblyof claim 2, wherein the crank arm is configured with a roller thatengages the translating structure during movement of the translatingstructure from the stowed position to a partially deployed position thatis between the stowed position and the deployed position.
 4. Theassembly of claim 3, wherein the roller disengages the translatingstructure when the crank arm engages a stop on the blocker door.
 5. Theassembly of claim 1, wherein the folding linkage is configured toinitiate movement of the blocker door relative to the translatingstructure substantially simultaneously with initiation of movement ofthe translating structure from the stowed position towards the deployedposition.
 6. The assembly of claim 1, wherein the folding linkage isconfigured to pivot the blocker door radially inwards as soon as thetranslating structure begins to translate axially from the stowedposition towards the deployed position.
 7. The assembly of claim 1,wherein the folding linkage comprises a bi-folding linkage.
 8. Theassembly of claim 1, further comprising a fixed cascade structure. 9.The assembly of claim 1, wherein the blocker door is one of a pluralityof blocker doors; the folding linkage is one of a plurality of foldinglinkages; and each of the blocker doors is associated with a single oneof the folding linkages.
 10. The assembly of claim 1, wherein theblocker door extends laterally between opposing blocker door sides; andthe folding linkage is aligned laterally midway between the opposingblocker door sides.
 11. The assembly of claim 1, wherein the foldinglinkage is nested within a channel in the blocker door and within achannel in the translating structure when the translating structure isin the stowed position.